Works are expected to last until autumn 2016 but business life will continue during the works for the 200 shops and 150 stall holders in the market place.
The redevelopment includes building a new event space and dedicated café area, maintenance work on the 1976 and 1981 halls, plus replacing both roofs, introduction of a new covered daily market within the 1976 hall and new pedestrian routes linking the three entrances. There will also be improved signage, screens and maps to help shoppers navigate the space.
The contract was awarded via the YORbuild framework.
Interserve divisional director John Gittins said: “There are a number of challenges with completing work around a live retail environment. To mitigate these, we have already undertaken some initial enabling works and will complete some of the work outside trading hours to minimise disruption.
“As the building is listed, we will be working closely with English Heritage and the conservation team.”